1. Field of the Invention
The present invention relates to a thermal spray material, a thermal spray coating formed with the thermal spray material, and a thermal spray coated article.
2. Description of the Related Art
Technologies to coat substrate surfaces with various materials to add new functionalities have been conventionally used in various fields. One known example of such surface coating technologies is thermal spray technology where a substrate surface is thermal-sprayed with particles formed with a material such as ceramic softened or melted by combustion or electrical energy, thereby to form a thermal spray coating made of the material.
In industries of manufacturing semiconductor devices and the like, generally, the surfaces of semiconductor substrates are very finely processed by dry etching with plasma of a halogen gas such as fluorine, chlorine and bromine. After the dry etching process, the chamber (vacuum container) from which the semiconductor substrates have been removed are cleaned with oxygen gas plasma. During this, in the chamber, there are possibilities of erosion occurring on members exposed to the highly reactive oxygen gas plasma or halogen gas plasma. If the erosion areas fall as particles from these members, these particles may be deposited on the semiconductor substrates, becoming contaminants (or “particles” hereinafter) to cause circuit defects.
Thus, conventionally, in equipment for manufacturing semiconductor devices, to reduce the formation of particles, members exposed to plasma of oxygen gas, halogen gases and the like are provided with a thermal spray ceramic coating with plasma erosion resistance. For instance, International Application Publication No. 2014/002580 teaches that by using granules that comprise an yttrium oxyfluoride at least partially as the thermal spray material, a thermal spray coating can be formed with high resistance to plasma erosion.